Saturday, August 20, 2011

Satellite radar imagery reveals 'amazing flows' of Antarctic ice

The first detailed map of ice flow across the entire continent of Antarctica has been developed, showing "amazing flows" from the continent's center.

"We're seeing amazing flows from the heart of the continent that had never been described before," said researcher Eric Rignot, a glaciologist at the University of California at Irvine and NASA's Jet Propulsion

Laboratory. "This is like seeing a map of all the oceans' currents for the first time."

Since the vast majority of Earth's ice is located on Antarctica, and melting polar ice sheets could potentially dramatically raise sea level, the new digital mosaic released on Thursday could help researchers understand how Antarctica might change under the steadily warming global climate.

Antarctica's ice sheet is made up of glaciers, which are essentially slowly flowing rivers of ice. The glaciers end in ice shelves, which float on the ocean's surface and occasionally spawn icebergs.

Conventionally, ground-based stations measure Antarctic ice movements, but there are relatively few stations compared with the size of the southernmost continent, which has led to an incomplete picture of these motions.

To look over all of Antarctica, the new map incorporated high-resolution satellite radar data of the continent's ice flows from the Canadian Space Agency, the European Space Agency and the Japan Aerospace Exploration Agency between 2007 and 2009.

It reveals that ice motions on Antarctica depend mostly on a vast, complex network of narrow rivers of ice reaching hundreds of miles over the whole of the continent.